U.S. patent application number 15/237792 was filed with the patent office on 2018-02-22 for clutch system.
The applicant listed for this patent is FORD GLOBAL TECHNOLOGIES, LLC. Invention is credited to Bradley Ronald HEUVER, Brandon David LINT.
Application Number | 20180051756 15/237792 |
Document ID | / |
Family ID | 59814710 |
Filed Date | 2018-02-22 |
United States Patent
Application |
20180051756 |
Kind Code |
A1 |
LINT; Brandon David ; et
al. |
February 22, 2018 |
CLUTCH SYSTEM
Abstract
A clutch includes a piston, backing plate, spring, and spring
retainer. The piston and the backing plate define a balance chamber
therebetween. The piston has a protrusion that extends into and
defines a pocket in the chamber. The spring is disposed within the
pocket and is configured to disengage the piston from a clutch
pack. The spring retainer is disposed between the spring and the
backing plate. The retainer extends from the backing plate and into
the chamber beyond an end of the protrusion.
Inventors: |
LINT; Brandon David;
(Dexter, MI) ; HEUVER; Bradley Ronald; (South
Lyon, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
FORD GLOBAL TECHNOLOGIES, LLC |
Dearborn |
MI |
US |
|
|
Family ID: |
59814710 |
Appl. No.: |
15/237792 |
Filed: |
August 16, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F16D 25/12 20130101;
F16D 25/0638 20130101; F16D 25/06 20130101; F16D 13/52 20130101;
F16D 25/10 20130101 |
International
Class: |
F16D 25/10 20060101
F16D025/10; F16D 25/12 20060101 F16D025/12; F16D 25/06 20060101
F16D025/06; F16D 13/52 20060101 F16D013/52 |
Claims
1. A clutch comprising: a piston and a backing plate defining a
balance chamber therebetween, the piston having a protrusion
extending into and defining a pocket in the chamber; a spring
disposed within the pocket and configured to disengage the piston
from a clutch pack; and a spring retainer, disposed between the
spring and the backing plate, extending from the backing plate into
the chamber beyond an end of the protrusion, defining an orifice
between inner and outer diameters of the retainer, wherein the
spring is disposed within the orifice, and having a first
projection between the orifice and the inner diameter of the
retainer that extends into the chamber beyond an end of the
protrusion when the piston is disengaged.
2. (canceled)
3. The clutch of claim 1 wherein the retainer has a second
projection that extends from the orifice, internal relative to an
inner diameter of the spring, and into the chamber beyond the end
of the protrusion when the piston is disengaged.
4-5. (canceled)
6. The clutch of claim 1, wherein the first projection of the
retainer extends along an angle toward the backing plate to direct
flow of hydraulic fluid into the chamber.
7. The clutch of claim 1, wherein a surface of the retainer, that
extends into the chamber and faces an internal surface of the
piston, has a profile that parallels the internal surface of the
piston.
8. A clutch module comprising: a first clutch having a first piston
and a first backing plate defining a first balance chamber
therebetween, the first piston having a first protrusion extending
into and defining a pocket in the first chamber, and a first spring
retainer extending from the first backing plate into the first
chamber beyond an end of the first protrusion; a second clutch
having a second piston and a second backing plate defining a second
balance chamber therebetween; and a fluid circuit configured to
deliver hydraulic fluid in series to the first chamber and the
second chamber such that hydraulic fluid is delivered to the second
chamber after the first chamber becomes filled with hydraulic
fluid.
9. The clutch module of claim 8, wherein the second piston has a
second protrusion extending into the second chamber and further
comprising a second spring retainer extending from the second
backing plate into the second chamber beyond an end of the second
protrusion.
10. The clutch module of claim 8, wherein the first retainer
defines an orifice between inner and outer diameters of the first
retainer, and further comprising a spring being disposed within the
orifice and the pocket.
11. The clutch module of claim 10, wherein the first retainer has a
projection that extends from the orifice, internal relative to an
inner diameter of the spring, and into the first chamber beyond the
end of the first protrusion.
12. The clutch module of claim 10, wherein the first retainer has a
projection between the orifice and the outer diameter of the first
retainer that extends into the first chamber beyond an end of the
first protrusion.
13. The clutch module of claim 10, wherein the first retainer has a
projection between the orifice and the inner diameter of the first
retainer that extends into the first chamber beyond an end of the
first protrusion.
14. The clutch module of claim 13, wherein the projection of the
first retainer extends along an angle towards backing plate to
direct flow of hydraulic fluid into the first chamber.
15. A clutch comprising: a piston having a first internal surface
opposing a second internal surface of a backing plate, the first
and second internal surfaces defining a balancing chamber
therebetween, the first internal surface having a protrusion
extending into and defining a pocket in the chamber; and a spring
retainer, disposed within the chamber, secured to the second
internal surface, having a profile that faces and parallels the
first internal surface, defining an orifice between inner and outer
diameters of the retainer, and having a first projection that
extends from the orifice, internal relative to an inner diameter of
a spring that is disposed with orifice, and into the chamber beyond
an end of the protrusion when the piston is disengaged.
16-18. (canceled)
19. The clutch of claim 15, wherein the retainer has a second
projection between the orifice and the inner diameter of the
retainer that extends into the chamber beyond an end of the
protrusion when the piston is disengaged.
20. The clutch of claim 19, wherein the second projection of the
retainer extends along an angle toward the backing plate to direct
flow of hydraulic fluid into the chamber.
21. A clutch comprising: a piston and a backing plate defining a
chamber therebetween, the piston having a protrusion extending into
the chamber; a spring retainer, secured to the plate within the
chamber, defining an orifice between inner and outer diameters of
the retainer, and having a projection that extends from the orifice
and into the chamber beyond the protrusion when the piston is
disengaged; and a spring disposed around the protrusion within the
orifice.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to clutches that may be
utilized in vehicle transmissions.
BACKGROUND
[0002] Vehicle transmissions, transaxles, or other mechanisms that
employ more than one gearing ratio between an input and an output,
may transition between various gear ratios by engaging and
disengaging various clutches. The clutches may comprise alternating
friction plates and separator plates that are configured to
selectively couple two rotating elements (shafts, gears, etc.).
SUMMARY
[0003] A clutch includes a piston, backing plate, spring, and
spring retainer. The piston and the backing plate define a balance
chamber therebetween. The piston has a protrusion that extends into
and defines a pocket in the chamber. The spring is disposed within
the pocket and is configured to disengage the piston from a clutch
pack. The spring retainer is disposed between the spring and the
backing plate. The retainer extends from the backing plate and into
the chamber beyond an end of the protrusion.
[0004] A clutch module includes a first clutch, second clutch, and
fluid circuit. The first clutch has a first piston and a first
backing plate that define a first balance chamber therebetween, the
first piston has a first protrusion that extends into and defines a
pocket in the first chamber, and a first spring retainer that
extends from the first backing plate and into the first chamber
beyond an end of the first protrusion. The second clutch has a
second piston and a second backing plate that define a second
balance chamber therebetween. The fluid circuit is configured to
deliver hydraulic fluid in series to the first chamber and the
second chamber such that hydraulic fluid is delivered to the second
chamber after the first chamber becomes filled with hydraulic
fluid.
[0005] A clutch includes a piston, backing plate, and spring
retainer. The piston has a first internal surface opposing a second
internal surface of the backing plate. The first and second
internal surfaces define a balancing chamber therebetween. The
first internal surface has a protrusion extending into the chamber.
The protrusion and defines a pocket in the chamber. The spring
retainer is disposed within the chamber, secured to the second
internal surface, and has a profile that faces and parallels first
internal surface.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a cross-sectional view representative of a clutch
module;
[0007] FIG. 2 is an isometric view of a first embodiment of a
spring retaining mechanism; and
[0008] FIG. 3 is an isometric view of a second embodiment of a
spring retaining mechanism.
DETAILED DESCRIPTION
[0009] Embodiments of the present disclosure are described herein.
It is to be understood, however, that the disclosed embodiments are
merely examples and other embodiments may take various and
alternative forms. The figures are not necessarily to scale; some
features could be exaggerated or minimized to show details of
particular components. Therefore, specific structural and
functional details disclosed herein are not to be interpreted as
limiting, but merely as a representative basis for teaching one
skilled in the art to variously employ the embodiments. As those of
ordinary skill in the art will understand, various features
illustrated and described with reference to any one of the figures
may be combined with features illustrated in one or more other
figures to produce embodiments that are not explicitly illustrated
or described. The combinations of features illustrated provide
representative embodiments for typical applications. Various
combinations and modifications of the features consistent with the
teachings of this disclosure, however, could be desired for
particular applications or implementations.
[0010] A gearing arrangement is a collection of rotating elements
and clutches configured to impose specified speed relationships
among elements. Some speed relationships, called fixed speed
relationships, are imposed regardless of the state of any clutches.
A gearing arrangement imposing only fixed relationships is called a
fixed gearing arrangement. Other speed relationships are imposed
only when particular clutches are fully engaged. A gearing
arrangement that selectively imposes speed relationships is called
a shiftable gearing arrangement. A discrete ratio transmission has
a shiftable gearing arrangement that selectively imposes a variety
of speed ratios between an input shaft and an output shaft.
[0011] A group of elements are fixedly coupled to one another if
they are constrained to rotate as a unit in all operating
conditions. Elements can be fixedly coupled by spline connections,
welding, press fitting, machining from a common solid, or other
means. Slight variations in rotational displacement between fixedly
coupled elements can occur such as displacement due to lash or
shaft compliance. In contrast, two elements are selectively coupled
by a clutch when the clutch constrains them to rotate as a unit
whenever the clutch is fully engaged and they are free to rotate at
distinct speeds in at least some other operating condition.
Clutches include actively controlled devices such as hydraulically
or electrically actuated clutches and passive devices such as one
way clutches. A clutch that holds an element against rotation by
selectively connecting the element to the housing may be called a
brake.
[0012] Referring to FIG. 1, a cross-sectional view of a clutch
module 10 is illustrated. The clutch module 10 includes a first
clutch 12 and a second clutch 14. The clutch module 10 may be part
of a transmission or transaxle of a vehicle, such as an
automobile.
[0013] More specifically, the first clutch 12 and the second clutch
14 may be hydraulic clutches. The first clutch 12 may be configured
to selectively couple a first rotating element 18 to a second
rotating element 20. The second clutch 14 may be configured to
selectively couple the second rotating element 20 to a third
rotating element 22. Alternatively, the second clutch 14 may be
configured to selectively couple third and fourth rotating elements
that are not common with the rotating elements that the first
clutch 12 is configured to selectively couple to each other.
Furthermore, the first clutch 12 and/or the second clutch 14 maybe
brakes that are configured to selectively couple one rotating
element to a static element, such as a case or housing (e.g., a
clutch module housing, transmission housing, or transaxle
housing).
[0014] The first clutch 12 includes a first clutch pack 24 that
includes friction plates and separator plates that are fixedly
coupled, in alternating configuration, to either the first rotating
element 18 or the second rotating element 20. A first piston 26 is
configured to engage and disengage the first clutch pack 24 in
order to couple and decouple the first rotating element 18 to and
from the second rotating element 20. The first piston 26 engages
the first clutch pack 24 when high pressure hydraulic fluid is
directed into a first chamber 28 located on an apply side of the
first piston 26. The high pressure hydraulic fluid may be directed
into the first chamber 28 through a channel that is connected to a
high pressure fluid circuit. Low pressure hydraulic fluid may also
be directed into a first balancing dam chamber (or first balance
chamber) 30 located on the opposing side of the first piston 26
relative to the first chamber 28 located on the apply side of the
first piston 26. The low pressure hydraulic fluid may be directed
into the first balancing dam chamber 30 through a channel that is
connected to a low pressure fluid circuit. A balance dam creates a
centrifugal hydraulic pressure that opposes and balances
centrifugal hydraulic pressure developed in the first chamber 28
located on the apply side of the first piston 26. These centrifugal
pressures are caused by rotation of the components of the first
clutch 12. Directing hydraulic fluid into the first balance dam
chamber 30 eliminates or reduces the pressure effects caused by the
speed of rotation so that the control system pressure (i.e., the
hydraulic pressure commanded to the first chamber 28 located on the
apply side of the first piston 26) alone creates the necessary
force for the first piston 26 to engage the first clutch pack
24.
[0015] The first clutch 12 may also include a first backing plate
32 disposed between the first piston 26 and the first clutch pack
24. The first balancing dam chamber 30 may be defined between the
first piston 26 and the first backing plate 32. Hydraulic fluid may
be vented from the first balancing dam chamber 30 while engaging
the first piston 26 and the first clutch pack 24. A first
compression spring 34 is configured to disengage the first piston
26 from the first clutch pack 24 when hydraulic fluid is vented
from the first chamber 28 located on the apply side of the first
piston 26. The first compression spring 34 may push against the
first backing plate 32, which provides a reaction force, to
disengage the first piston 26 from the first clutch pack 24. A
first spring retainer 36 may be disposed between the first backing
plate 32 and the first compression spring 34. An additional spring
retainer may be disposed between the first piston 26 and the first
compression spring 34.
[0016] The second clutch 14 includes a second clutch pack 38 that
includes friction plates and separator plates that are fixedly
coupled, in alternating configuration, to either the second
rotating element 20 or the third rotating element 22. A second
piston 40 is configured to engage and disengage the second clutch
pack 38 in order to couple and decouple the second rotating element
20 to and from the third rotating element 22. The second piston 40
engages the second clutch pack 38 when high pressure hydraulic
fluid is directed into a second chamber 42 located on an apply side
of the second piston 40. The high pressure hydraulic fluid may be
directed into the second chamber 42 through a channel that is
connected to a high pressure fluid circuit. Low pressure hydraulic
fluid may also be directed into a second balancing dam chamber (or
second balance chamber) 44 located on the opposing side of the
second piston 40 relative to the second chamber 42 located on the
apply side of the second piston 40. The low pressure hydraulic
fluid may be directed into the second balancing dam chamber 44
through a channel that is connected to a low pressure fluid
circuit. A balance dam creates a centrifugal hydraulic pressure
that opposes and balances centrifugal hydraulic pressure developed
in the second chamber 42 located on the apply side of the second
piston 40. These centrifugal pressures are caused by rotation of
the components of the second clutch 14. Directing hydraulic fluid
into the second balance dam chamber 44 eliminates or reduces the
pressure effects caused by the speed of rotation so that the
control system pressure (i.e., the hydraulic pressure commanded to
the second chamber 42 located on the apply side of the second
piston 40) alone creates the necessary force for the second piston
40 to engage the second clutch pack 38.
[0017] The second clutch 14 may also include a second backing plate
46 disposed between the second piston 40 and the second clutch pack
38. The second balancing dam chamber 44 may be defined between the
second piston 40 and the second backing plate 46. Hydraulic fluid
may be vented from the second balancing dam chamber 44 while
engaging the second piston 40 and the second clutch pack 38. A
second compression spring 48 is configured to disengage the second
piston 40 from the second clutch pack 38 when hydraulic fluid is
vented from the second chamber 42 located on the apply side of the
second piston 40. The second compression spring 48 may push against
the second backing plate 46, which provides a reaction force, to
disengage the second piston 40 from the second clutch pack 38. A
second spring retainer 50 may be disposed between the second
backing plate 46 and the second compression spring 48. An
additional spring retainer may be disposed between the second
piston 40 and the second compression spring 48.
[0018] The clutch module 10 includes a fluid circuit 52 is
configured to deliver hydraulic fluid to the first balancing dam
chamber 30 and the second balancing dam chamber 44. The fluid
circuit 52 may be a low pressure hydraulic fluid circuit. The fluid
circuit 52 may include a feed line 54 that supplies hydraulic fluid
to the fluid circuit 52. A device, such as a pump, may be used to
supply hydraulic fluid from the feed line 54 to the fluid circuit
52. The fluid circuit may include a first inlet 56 to the first
balancing dam chamber 30 and a second inlet 58 to the second
balancing dam chamber 44. The fluid circuit 52 may be configured to
deliver hydraulic fluid, in series, first to the first balancing
dam chamber 30 and then to the second balancing dam chamber 44
after the first balancing dam chamber 30 has become filled with
hydraulic fluid. Alternatively, the fluid circuit 52 may be
configured to deliver hydraulic fluid or in parallel,
simultaneously filling the first balancing dam chamber 30 and the
second balancing dam chamber 44.
[0019] Referring to FIGS. 1-3, the first piston 26, first spring
retainer 36, second piston 40, and second spring retainer 50 are
described in further detail. The first piston 26 may include a
first protrusion 60 that extends into the first balancing dam
chamber 30. The first protrusion 60 may define a first pocket 62
within the first balancing dam chamber 30. The first pocket 62 may
be sized to receive the first compression spring 34. The first
compression spring 34 may be disposed within the first pocket 62.
The first spring retainer 36 may be disposed within the first
balancing dam chamber 30. The first spring retainer 36 may extend
from the first backing plate 32 and into the first balancing dam
chamber 30 beyond an end of the first protrusion 60. The first
piston 26 may have a first internal surface 64. The first backing
plate 32 may have a second internal surface 66 that opposes the
first internal surface 64 of the first piston 26. The first
balancing dam chamber 30 may be defined between the first internal
surface 64 and the second internal surface 66. The first protrusion
60 may extend from the first internal surface 64 of the first
piston 26 and into the first balancing dam chamber 30. The first
spring retainer 36 may be positioned such that a backside (or back
surface) of the first spring retainer 36 comes into contact with
the second internal surface 66 of the first backing plate 32. More
specifically, the backside of the first spring retainer 36 may be
secured to the second internal surface 66 of the first backing
plate 32. A front side (or front surface) of the first spring
retainer 36 may face the first internal surface 64 of the first
piston 26. The front side of the first spring retainer 36 may have
a contour or profile 68, where at least a portion of the profile 68
is substantially parallel with the first internal surface 64 of the
first piston 26. Substantially parallel may include any deviation
from parallel that ranges from 0 mm to 3 mm.
[0020] The first spring retainer 36 may define a first orifice (or
plurality of first orifices) 70 between an inner diameter 72 of the
first spring retainer 36 and an outer diameter 74 of the first
spring retainer 36. The first compression spring (or plurality of
first compression springs) 34 may be disposed within the first
orifice 70 along with being disposed within the first pocket 62
defined by first protrusion 60 of the first piston 26. The first
spring retainer 36 may include a first projection (or plurality of
first projections) 76 that extends from the first orifice 70 and
into the first balancing dam chamber 30 beyond an end of the first
protrusion 60 of the first piston 26. The first projection 76 may
also be positioned internally relative to an inner diameter 78 of
the first compression spring 34. The first spring retainer 36 may
also include a second projection 80 between the first orifice 70
and the outer diameter 74 of the first spring retainer 36. The
second projection 80 may also extend into the first balancing dam
chamber 30 beyond an end of the first protrusion 60 of the first
piston 26. The first spring retainer 36 may further include a third
projection 82 between the first orifice 70 and the inner diameter
72 of the first spring retainer 36. The third projection 82 may
also extend into the first balancing dam chamber 30 beyond an end
of the first protrusion 60 of the first piston 26. The third
projection 82 may extend along an angle towards the first backing
plate 32, such that the thickness of the third projection decreases
as you move radially inward from the first orifice 70 to the inner
diameter 72 of the first spring retainer 36, in order to direct
hydraulic fluid into the first balancing dam chamber 30.
[0021] The second piston 40 may include a second protrusion 84 that
extends into the second balancing dam chamber 44. The second
protrusion 84 may define a second pocket 86 within the second
balancing dam chamber 44. The second pocket 86 may be sized to
receive the second compression spring 48. The second compression
spring 48 may be disposed within the second pocket 86. The second
spring retainer 50 may be disposed within the second balancing dam
chamber 44. The second spring retainer 50 may extend from the
second backing plate 46 and into the second balancing dam chamber
44 beyond an end of the second protrusion 84. The second piston 40
may have a third internal surface 88. The second backing plate 46
may have a fourth internal surface 90 that opposes the third
internal surface 88 of the second piston 40. The second balancing
dam chamber 44 may be defined between the third internal surface 88
and the fourth internal surface 90. The second protrusion 84 may
extend from the third internal surface 88 of the second piston 40
and into the second balancing dam chamber 44. The second spring
retainer 50 may be positioned such that a backside (or back
surface) of the second spring retainer 50 comes into contact with
the fourth internal surface 90 of the second backing plate 46. More
specifically, the backside of the second spring retainer 50 may be
secured to the fourth internal surface 90 of the second backing
plate 46. A front side (or front surface) of the second spring
retainer 50 may face the third internal surface 88 of the second
piston 40. The front side of the second spring retainer 50 may have
a contour or profile 92, where at least a portion of the profile 92
is substantially parallel with the third internal surface 88 of the
second piston 40. Substantially parallel may include any deviation
from parallel that ranges from 0 mm to 3 mm.
[0022] The second spring retainer 50 may define a second orifice
(or plurality of second orifices) 94 between an inner diameter 96
of the second spring retainer 50 and an outer diameter 98 of the
second spring retainer 50. The second compression spring (or
plurality of second compression springs) 48 may be disposed within
the second orifice 94 along with being disposed within the second
pocket 86 defined by second protrusion 84 of the second piston 40.
The second spring retainer 50 may include a fourth projection (or
plurality of fourth projections) 100 that extends from the second
orifice 94 and into the second balancing dam chamber 44 beyond an
end of the second protrusion 84 of the second piston 40. The fourth
projection 100 may also be positioned internally relative to an
inner diameter 101 of the second compression spring 48. The second
spring retainer 50 may also include a fifth projection 102 between
the inner diameter 96 and the outer diameter 98 of the second
spring retainer 50. The fifth projection 102 may also extend into
the second balancing dam chamber 44 beyond an end of the second
protrusion 84 of the second piston 40. The fifth projection 102 may
extend along an angle towards the second backing plate 46, such
that the thickness of the third projection decreases as you move
radially inward from the outer diameter 98 toward the inner
diameter 96 of the second spring retainer 50, in order to direct
hydraulic fluid into the second balancing dam chamber 44.
[0023] The first spring retainer 36 and the second spring retainer
50 are configured to reduce the fill volumes (the amount of space
that receives hydraulic fluid when the clutches are being operated)
of the first balancing dam chamber 30 and the second balancing dam
chamber 44, respectively. The first spring retainer 36 and the
second spring retainer 50 reduce the fill volumes of the balancing
dam chambers by occupying a portion of the total volume of the
balancing dam chambers. The first spring retainer 36 may occupy
anywhere from 20% to 90% of the volume of the first balancing dam
chamber 30. The second spring retainer 50 may occupy anywhere from
20% to 90% of the volume of the second balancing dam chamber 44.
The time required to fill the balancing dam chambers is therefore
reduced since a smaller volume of the balancing dam chambers needs
to be filled when the clutches are operational. Reducing the time
required to fill the balancing dam chambers may advantageous in
clutches used in transmissions or transaxles for vehicles that have
an engine auto start/stop function which cuts off the supply of
hydraulic fluid when the engine stopped.
[0024] The words used in the specification are words of description
rather than limitation, and it is understood that various changes
may be made without departing from the spirit and scope of the
disclosure. As previously described, the features of various
embodiments may be combined to form further embodiments that may
not be explicitly described or illustrated. While various
embodiments could have been described as providing advantages or
being preferred over other embodiments or prior art implementations
with respect to one or more desired characteristics, those of
ordinary skill in the art recognize that one or more features or
characteristics may be compromised to achieve desired overall
system attributes, which depend on the specific application and
implementation. As such, embodiments described as less desirable
than other embodiments or prior art implementations with respect to
one or more characteristics are not outside the scope of the
disclosure and may be desirable for particular applications.
* * * * *